/* Copyright (C) 2004 - 2006  db4objects Inc.  http://www.db4o.com

This file is part of the db4o open source object database.

db4o is free software; you can redistribute it and/or modify it under
the terms of version 2 of the GNU General Public License as published
by the Free Software Foundation and as clarified by db4objects' GPL 
interpretation policy, available at
http://www.db4o.com/about/company/legalpolicies/gplinterpretation/
Alternatively you can write to db4objects, Inc., 1900 S Norfolk Street,
Suite 350, San Mateo, CA 94403, USA.

db4o is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
59 Temple Place - Suite 330, Boston, MA  02111-1307, USA. */
namespace Db4objects.Db4o.Internal
{
	/// <exclude></exclude>
	public class VersionFieldMetadata : Db4objects.Db4o.Internal.VirtualFieldMetadata
	{
		internal VersionFieldMetadata(Db4objects.Db4o.Internal.ObjectContainerBase stream
			) : base()
		{
			i_name = Db4objects.Db4o.Ext.VirtualField.VERSION;
			i_handler = new Db4objects.Db4o.Internal.Handlers.LongHandler(stream);
		}

		public override void AddFieldIndex(Db4objects.Db4o.Internal.Marshall.MarshallerFamily
			 mf, Db4objects.Db4o.Internal.ClassMetadata yapClass, Db4objects.Db4o.Internal.StatefulBuffer
			 writer, Db4objects.Db4o.Internal.Slots.Slot oldSlot)
		{
			writer.WriteLong(writer.GetStream().GenerateTimeStampId());
		}

		public override void Delete(Db4objects.Db4o.Internal.Marshall.MarshallerFamily mf
			, Db4objects.Db4o.Internal.StatefulBuffer a_bytes, bool isUpdate)
		{
			a_bytes.IncrementOffset(LinkLength());
		}

		internal override void Instantiate1(Db4objects.Db4o.Internal.Transaction a_trans, 
			Db4objects.Db4o.Internal.ObjectReference a_yapObject, Db4objects.Db4o.Internal.Buffer
			 a_bytes)
		{
			a_yapObject.VirtualAttributes().i_version = a_bytes.ReadLong();
		}

		internal override void Marshall1(Db4objects.Db4o.Internal.ObjectReference a_yapObject
			, Db4objects.Db4o.Internal.StatefulBuffer a_bytes, bool a_migrating, bool a_new)
		{
			Db4objects.Db4o.Internal.ObjectContainerBase stream = a_bytes.GetStream().i_parent;
			Db4objects.Db4o.Internal.VirtualAttributes va = a_yapObject.VirtualAttributes();
			if (!a_migrating)
			{
				va.i_version = stream.GenerateTimeStampId();
			}
			if (va == null)
			{
				a_bytes.WriteLong(0);
			}
			else
			{
				a_bytes.WriteLong(va.i_version);
			}
		}

		public override int LinkLength()
		{
			return Db4objects.Db4o.Internal.Const4.LONG_LENGTH;
		}

		internal override void MarshallIgnore(Db4objects.Db4o.Internal.Buffer writer)
		{
			writer.WriteLong(0);
		}
	}
}
